1. Field of the Invention
This invention relates to improvements in heating and cooling systems and relates particularly to improvements in air conditioning and chilling systems. Particularly, the invention relates to a dedicated heat recovery chiller and control systems for such a chiller.
The dedicated heat recovery chiller and control system of the present invention utilizes heat otherwise rejected and wasted from a condenser circuit of a refrigeration system to offset heating load which would otherwise need to be provided from a heating source. This system raises the overall thermal efficiency of a building system, reduces energy consumption overall, and saves energy costs.
Recent developments in air conditioning systems involve the utilization of modular refrigeration units each having an evaporator and condenser in heat exchange relation with the fluid to be cooled and/or heated. With the modular system, each refrigeration unit is provided with headers for supply and return of the heat exchange fluid. A plurality of refrigeration units is connected in parallel, and the heat exchange fluid circulates through each evaporator and condenser heat exchanger.
The control of such a modular system enables individual refrigeration units to be operated in accordance with the load on the system. Thus, in times of high load, all refrigeration units will be operating to provide a specific heating and/or cooling capacity. When the load is reduced, refrigeration units may be down loaded, or made inoperative, thus reducing the operating costs of the system and resting units which are not required.
These units are interconnected and coordinated in the present invention to create a dedicated heat recovery chiller system. In this system, heat normally rejected to atmosphere from the condenser circuit of the refrigeration cycle is instead captured, controlled, and utilized to displace heat load otherwise provided by a conventional heating circuit.
The present invention in particular pertains to improvements in dedicated heat recovery chiller-heaters having multiple stages of heat transfer.
2. Description of the Related Art
In the past, heat from the condenser circuit of an air conditioning system would be rejected to atmosphere, and thereby wasted.
The modular refrigeration system overcomes a number of disadvantages of previous systems, particularly with regard to system breakdowns and system expansion. The modular system also provides substantial economies in being able to operate only those refrigeration units necessary for the load at any particular time. Power is therefore saved in not having to run refrigeration units which are unnecessary, or in running units at lower than optimum peak operating efficiency.
It is desirable to provide a dedicated heat recovery chiller system to improve the overall thermal efficiency of a building system.
It is also desirable to provide an improved heating and/or cooling system for a modular refrigeration system having a multiplicity of refrigeration units in which the flow of heat exchange fluid through the condenser and/or chiller of each unit is dependent on the operating state of that unit.
It is also desirable to optimize the power consumed by a modular refrigeration system when operated at less than maximum capacity by reducing the flow of heat exchange fluid through the system.
It is further desirable to reduce the flow of heat exchange fluid through heat exchangers of modular units which are not operating and, at the same time, maintain substantially constant pressure differentials throughout the heating and/or cooling system.
Finally, it has been desired to arrange for elevated temperatures produced by the system to displace more of the conventional heat load requirements as compared to the temperatures available from conventional prior art systems.
These and other prior art deficiencies are addressed and solved by the present invention.